Tread portion of an automobile tire



FIG. 1 is a front view of a tread portion of an automobile tire, it being understood that the tread pattern repeats uniformly throughout the circumference of the tire;

FIG. 2 is a perspective view thereof;

FIG. 3 is a left side view thereof, the right side view being identical thereto; and,

FIG. 4 is a fragmentary enlarged view showing the details of the tread portion thereof.

The broken lines in the drawing figures illustrate environmental structure only, and form no part of the claimed design. 

The ornamental design for a tread portion of an automobile tire, as shown and described. 